Block for holding printing plates



June 4, 1929. 4w. A. MATHERS A BLOCK FOR HOLDING PRINTING PLATES Fild Sept. 25, 1926 foundation for the printing plates.

Patented .lune 4, 1929. e

Unirse arras ers y c anais WILLIAM A. MATHERS, or sourir WAvnn-LY, 'rnivnsrnvania As'srenort rro Uniden STEEL BLOCK COMPANY, or WAvnnLY, iinvr YORK.

roar., .a Conroe-Arron or NEW BLOCK FOR HOLDING ERINTING PLATES.

Application filed September 25, 1926. Serial No. 137,742.

The invention to which the following description applies concerns an improvement in the manufacture of blocks which are used to support the printing plates in a press. It is customary to fill in the chase of a press with a supporting block or blocks whichform a rigid backing upon which the electroplates or other printing plates are then clamped. In order to adjust therpositions of the respective printing plates the vided With al series of smaller sections spaced each from the other to provide t\vo series of parallel grooves. The series of grooves are arranged at right angles one to the other. A block of this type must' either be as exten sive as the printing matter to be printed or must lend itself to assembly from smaller units. It is'essential that both the individual units and the block itself shall present a rigid plane surface capable of withstanding considerable pressure without becoming deformed.

In order to obtain the results above indicated, the material used must be very strong and preferably the block is made of steel. It is however not practicableto produce 'such blocks in large sizes frommaterial such as steel and Where other material is substituted there is a consequent loss of rigidity and resistance to deformation.

I have vfound that steel may be used as av material for such a block by first constructine getther side by side to build up a bloclrof the requisite size. In this Way thebloclcs may be assembled `With the individual units lying side by side or With overlapping ends, forining an additional means of'insuringa firm It is a further object of my inventiontoY take advantage of the existence of the individual sections of the units to form part ofv the means for locking adjacent units together,

thus establishing a link or connection between the units for the full depth or transverse distance both for the base portions of the units and also the individual sections.V

In carrying out the locking of adjacent units of relatively hard metal together, it is a further object of this invention to provide a key, link, or other connecting'element which shall be readily insertable but by reason of being formed from relatively softer mate rial, such as brass er the like, will Een te a slight elegirse and thus Ear blocks are pro units of steel and then locking them todrawing the side Walls of the units together throughout their transverse extent or depth.

The above and otherradvantages'of this inf vention will be apparent from the following description of my preferred form'of block as illustrated in the accompanying drawings in which:

Fig. l is a plan view showin'gthe connected portions of two units; l

2 is a vertical section taken on a line 2 2 of Fig. l and showing the side Wall of one unit together with the connecting members; Fig. 3 is a vertical cross section onv theline 3 3 of Fig.` l;

Fig. 4 is a side elevation of the connecting element, and y V 5 is an enlarged fragmentary view shoiving the relative positions ofthe unit and connecting link.l

rlhe printing block is shown to consist of the units 6 and 7. These units may have any desired dimensions within the limitations of the material used. It is 'found that -When steel is used,it is not practicable to construct the units atgreater than the size eight by ten inches. In Fig. l the units. 6 and 7 have been shown as abutting with the end Wallsy 8, 8 even. It is however-possible to cause one unit to overlap the adjacent unit. l

Each unit consists in a base portion 9 which carries a plurality `of individual sec-l tions l0. These sections 10 consist of rectangular projections, the upper faces of which are customarily square and have a length of three picas on a side. The individual sections 10 are spaced apart by distancey of one pica. In this manner parallel grooves areprovided atrightangles Overtlie face of the block. As shown in Fig. 2 the grooves are. undercut as at 11 to provide yforreceiving the customary clamps.A The top surface of the sections maybe groovednto indicate distance measurements or left blank as occasion may demand., As above stated it is essential that the top surfaces of the ,sections lOf bein a common` plane surface' and that s FFlC -r e to connect adjacent side 'Walls of the units and to draw them together with the upper surfaces of the sections 10 in a common plane. These links 0r connecting members are provided in such number as may be found necessary Or desirable, and in the form illustrated are shown to be three in number spaced at intervals along the side row of the units and held by the section portions 12, 13, 14- of one of the units 6 and linking with the corresponding sections 15, 16, 17 of the adjacent unit 7. In this way the connecting members intersect the side wall 18 of each unit.

The sections 12 to 17 inclusive are transversely drilled to form passageways 19 suitably spaced from the side walls 18. The passageways 19 are then channeled out or slotted as at 20 to form a restricted slot in the face of the side walls for a purpose to be hereinafter' explained. In the form illustrated the passageways are cylindrical and perpendicularto the top surface of lthe block units.

The connecting link 21 is made of brass or some similar analogous relatively soft metal which will flow slightly when driven into the passageways and which willconform to them but at the same time exert enoughl tension throughout the length of the passageways or the transverse depth of the block units to maintain the abutting side walls in close contact with the top surfaces of the block units in a common plane. Each link consists in a pair of peg-like portions 22, 22 which are of slightly tapering form and disposed with their outer surfaces parallel, thus slightly converging towards the top as shown in Fig. 4. A web 23 connects the peg port-ions 22,22 and serves to permit some slight displacement of the metal when the link is driven into'place.` The link when in place extends throughout the full depth of the block units although an effect-ive connection may be' made by ra link of lesser length.

By reason of the slightly `tapering character of the 'members of 'the link andl the manner in which it is held in the passageways it follows that the link fits tightly against the outer walls of the passagcways and leaves a small opening shown in Fig. 5 to be of tapering size.

In assembling a supporting block from the above described units, the several. units are placed with their side walls adjacent and the end walls A'overlapping or not as may be desired. It is to be understood that the part sections which have the passageways are'arranged opposite each other providingrthe appropriate opening for the insertion of the link or connecting means. The latter is driven in from the upper side of the block with its top flush with the top of the block. This operation serves to contract the complementary part sections 12 and 15; 13 and 16, and 14 and 17. The linkage between the sidewalls of the blocks units is thus carried out at a number of points and in each instance throughout the depth of both the base` portion and the projecting sections 10. This serves to insure the block maintaining its top surface in a plane and to resist any tendency to be thrown out of plane by abnormal pressure.

The block may be built up of as many units as may be desired the same being bonded together on their side 0r end faces or walls in the mann er similar to that above described. If it is desiredto alterrthis arrangement the pins may be diiven out of the passageways upwardly and a new arrangement assembled.

By reason of the novelarrangement of parts above described it is possible to make a composite supporting block for printing out of material which would otherwise not be practicable. This extends the manifest advantages found in the use of hardened material and insures a long life without showing wear or deformation.'

While the above'description and illustration provide the preferred `form of device it is evident that numerous modifications in minor details or equivalent elements may be made without departingv from the scope of the inventionv as defined in the following claims.

What I claim is:

1. In combination, a unit for a backing block, said unit having a side wall, a passageway extending from the front to the rear entirely through said side wall, and a key slidably fitting in the passageway and coextensive therewith.

2. In combination, a backing block for printing comprising a plurality of units having abutting side walls, each unit having passageways extending from the front to the rear entirelyr through said side walls, and connecting means occupying the opposed passageways of adjacent units. y

3. In combination, a 'backing block for printing comprising a 'plurality of units having abutting side walls, each unit havingA passageways extending transversely thereof and opening on said side walls, the said passageways being widest along their inner portion and a key having spaced converg-` ing portions slidably fitting in the opposed passageways of adjacentunits.

In testimony whereof, I have hereunto affixed my signature. v

WILLIAM A. MATHERS. 

